A new study suggests that Jupiter's moon Europa, long considered a prime candidate for extraterrestrial life due to its vast subsurface ocean, may lack the geological activity necessary to support living organisms. Researchers found that weak tidal forces from Jupiter result in a calm and inactive seafloor. This challenges hopes for habitable conditions beneath the moon's icy crust.
Jupiter's moon Europa has captivated scientists with the possibility of a global ocean hidden under its 15- to 25-kilometer-thick ice shell, potentially holding more water than Earth. This salty liquid water layer, estimated to reach depths of up to 100 kilometers, sits above a rocky core that likely cooled billions of years ago, dissipating any significant internal heat.
Led by Paul Byrne, an associate professor of Earth, environmental, and planetary sciences at Washington University in St. Louis, the research models Europa's internal structure and the gravitational influences from its parent planet. Unlike the volcanically explosive moon Io, which experiences intense tidal heating due to its closer orbit, Europa's more distant and stable path results in milder forces. These weaker tides fail to generate enough heat for seafloor processes like tectonic shifts or hydrothermal vents, which are crucial for providing energy to potential life forms.
"If we could explore that ocean with a remote-control submarine, we predict we wouldn't see any new fractures, active volcanoes, or plumes of hot water on the seafloor," Byrne explained. "Geologically, there's not a lot happening down there. Everything would be quiet."
The study, published in Nature Communications in 2026, involved co-authors including Philip Skemer, Jeffrey Catalano, Douglas Wiens, and graduate student Henry Dawson, all affiliated with the McDonnell Center for the Space Sciences. Byrne emphasized the seafloor's importance, noting limited prior discussion despite extensive focus on the ocean itself. He added, "The energy just doesn't seem to be there to support life, at least today."
Despite these findings, exploration continues. NASA's Europa Clipper mission, set to arrive in 2031, will image the surface and refine data on the ice and ocean. Byrne remains optimistic: "I'm confident that there is life out there somewhere... That's why we explore -- to see what's out there." The research underscores Europa's quiet nature but does not rule out past activity or distant habitability elsewhere in the solar system.
